Company & Application 

A specialist in developing, manufacturing, and marketing performance additives for the use in the construction, electronics, consumer products, agriculture, automotive, oil & gas industries worldwide. Throughout their processes, raw material is fed into a milling machine along with additives needed to make the required final product.  

They’re mixed and milled to the required particle size. Filters ensure that only the required sizes pass through to the rotary dryer where all moisture is removed before the product is moved to the final hopper. From there the product is either bagged by weight or transferred directly to trucks for transport. 

The Challenge 

The milling and drying process is fully automated with manual interaction only required at the raw material loading and packing/loading stages. Production at the site consisted of four vertical mills spread over two different buildings. 

The drive to protect employees from potentially harmful dust is a priority for the company. They have identified prevention of exposure as the best form of protection and there’s a drive to reduce the amount of time that personnel spend inside the production facility. 

This ensures worker safety but generates its own problems, as process leakages aren’t detected until someone enters the production area and observes them. Due to the drive to limit exposure, this can lead to the loss of tons of product or raw material before the problem is found. This loss of yield comes at a significant cost to the business. 

The AIR XD plan 

In order to ensure that leaks were detected at different stages of the milling process, 14 AIR XD units were installed in different positions around the plant. The aim was to allow the company to more easily identify the location any leaks that were detected. 

Units were placed on different levels to monitor different parts of the process including the milling, drying and packing/loading areas and in order to meet the remote monitoring requirements of this company, the signal and alarm outputs from 

the AIR XD units were connected to a control panel located in the central control room.  

The AIR XD solution 

The AIR XD units were configured to focus on particles in the PM4.25 range, to specifically target dust generated from the processes, as opposed to all dust in the air. Since the majority of dust generated by the process was known to be silica, the particle density used in the airborne particulate density calculations were changed reflect this.  

After a short trial, alarm levels were selected which reflected higher than normal dust for the process. These alarms were later adjusted on some of the units to reflect higher dust levels typical of those areas. The ability to correlate the real-time AIR XD to the milling process showed its benefit to the customer within a few weeks of installation.  

AIR XD provided time stamped data with high temporal resolution, showing that high dust levels were present after machinery was switched off. This was found to be due 

to the fact that the extraction system for the mill shut off before the mill had finished spinning down releasing a cloud of dust into the area.  

This was quickly resolved by altering the mill program so that the extraction stayed on for 15 minutes after the mill was shut down. This small change to the process significantly reduced losses from the process and subsequent discoveries were also enabled further process improvements to be made for efficiency and cost savings. 

What it meant moving forward? 

• Real time monitoring of dust generated by the milling process has enabled effective remote detection of process leaks:
  This has allowed the customer to protect their personnel by limiting exposure whilst also maximising yield. 

• User programmable configuration of AIR XD has allowed the customer to focus detection on the dust generated by their process:
  This has enabled rapid and accurate detection of any process leaks. 

• Offline analysis of real time data collected by the AIR XD has allowed the customer to identify previously undetected issues with their process:
  This has allowed them to make small process improvements which have had a real positive impact on the profitability of the site.